This application is the U.S. national phase application of PCT International Application No. PCT/GB00/01264 filed Apr. 4, 2000.
1. Field of the Invention
This invention relates to a repairable vehicle pillar system, particularly but not exclusively for use with passenger service vehicles such as buses.
2. Description of the Related Art
The frame structures (or xe2x80x9csuperstructuresxe2x80x9d or xe2x80x9cbodiesxe2x80x9d) of passenger service vehicles such as buses are presently formed from the welding of a series of vertical pillars with intermediate horizontal struts or stringers. The outer panels are then attached to this frame structure. Currently, all pillars used in such structures extend down the complete length of the structure. However, in the everyday traffic environment that buses work in, the bottom level of panelling on buses and the like has become a major area for frequent repairs. This is the level of most car bumpers.
Presently, when a pillar becomes damaged, there are only two options available for its repair. Either the complete damaged pillar can be replaced, or the damaged part of the pillar is locally replaced. However, each of these methods incur their own problems. To change a complete pillar, approximately two man days are required. The cost of this and the cost of the down-time for the bus can be significant. Replacing the local damaged part of a pillar only is usually quicker, but a welded repair requires specialist training. Moreover, if aluminium is concerned, and many bus pillars are made from aluminium, specialist equipment is also required. Welded repairs also suffer from poor strength characteristics in comparison to a full length pillar.
It is an object of the present invention to provide a frame structure which is substantially quicker and easier to repair.
Thus, according to one aspect of the present invention, there is provided a vehicle frame structure having one or more wholly or substantially vertical pillars, and one or more wholly or substantially horizontal inter-connected struts, wherein the bottom section of at least one of the vertical pillars is separable from the remaining section of that pillar.
By being separable bottom sections, the bottom sections of such pillars, which are the sections of pillars which are most commonly damaged and need repair, can be quickly and easily replaced. Thus there is no need for major surgery to the whole frame structure.
Each bottom section of a pillar which is separable is separable in terms of being removably securable. The bottom section could be securable either to the remaining section of the pillar, to one or more horizontal struts, or to both. The bottom section could be removably secured using any suitable securing or fastening means, such as nuts and bolts. Each separable bottom section could be securable directly to the remaining part of the frame structure, or through one or more intermediate securing means such as plates, brackets, toggles, packer bars, flat bars, etc.
Preferably, the separable bottom section of the pillar extends from or near from the level of the lowest horizontal strut or struts. Each horizontal strut used in the frame structure could be continuous across the vertical pillars, or intermediate between the vertical pillars. A vehicle frame structure of the present invention could involve both forms of horizontal struts.
The separable bottom section may or may not be aligned with a vehicle pillar. Thus, the separable bottom sections may be positioned to suit other arrangements for the frame structure, e.g. wheel is arch positions. It would also allow a xe2x80x98standardizedxe2x80x99 frame structure or body to fit various different chassis.
According to one embodiment of the present invention, the frame structure includes one or more non-sectioned or continuous vertical pillars, in order to maintain its overall shape and/or its overall strength.
The frame structure of the present invention is applicable to any vehicle having one or more frame structures, upon which outer facings or panels are then attached. It is particularly suitable for passenger service vehicles such as buses, and especially the side frame structures of such vehicles.
It is also suitable for vehicles not having a conventional strong chassis that can easily be manipulated without affecting the overall strength and payload, e.g. the frame structure of so-called low floor buses, and similar passenger services vehicles. Chassis for such vehicles involve a weaker and more flexible mid-section, and so require the frame structure or body to be stronger. It was previously thought that to maintain strong body strength, continuous vertical pillars were still required. However the present invention has been found suitable for such buses, by ensuring strong conjunction of the separable pillars with the remaining frame structure.
According to a second aspect of the present invention there is provided a method of repairing a vehicle frame structure having one or more wholly or substantially vertical pillars and one or more wholly or substantially horizontal interconnected struts, the bottom section of a least one of the vertical pillars being separable from the remaining section of that pillar, wherein the bottom section is released and removed from the frame structure, and a new bottom section is secured to the frame structure.